As the world’s eyes remain firmly fixed on finding a vaccine for the novel coronavirus, in the fight to combat malaria, researchers are making big strides towards its elimination in the Greater Mekong Subregion (GMS) within the next decade.
Thanks to concentrated efforts by the World Health Organization (WHO) and the Global Fund, GMS countries Cambodia, Vietnam, Thailand, Myanmar and Laos have already cut their malaria case incidence by about 54% between 2012 and 2015, with malaria death rates falling by 84% in the same period.
However, the final sprint to total eradication could derail the already massive gains made, as the spread of drug resistance to the main antimalarial artemisinin has been detected in all five GMS countries.
Along the Cambodia-Thailand border, plasmodium falciparum malaria, the most deadly parasite strain, has become resistant to almost all available antimalarial drugs. Researchers are now racing against the clock in the race to eliminate malaria before momentum, interest and drug coffers run dry, and inevitable resurgence occurs.
Marking World Malaria Day on April 25, the Globe spoke with Dr Arjen Dondorp, head of malaria research at Mahidol-Oxford’s Tropical Medicine in Thailand, as well as the multimillion-dollar Global Fund-financed Regional Artemisinin-resistance Initiative (RAI), about the chances of complete malaria elimination in the GMS by 2030.
Under Dondorp’s lead, the RAI’s plan to eradicate the deadliest strain of malaria falciparum from the GMS by 2025, and all species of human malaria by 2030, is well within target.
“[In the] GMS, all governments have signed up to the elimination goals, the latest by 2030, but many countries aim for an earlier date,” Dondorp said optimistically, explaining the reason to be extra aggressive in the GMS now is due to the threat of parasite resistance.
Malaria rates in Southeast Asia account for just 3.4% globally, compared to the 213 million cases in African nations which combined make up 93% of global statistics.
But although the small number might seem reassuring, parasitic resistance to Artemisinin could thwart efforts.
“Malaria is treated by Artemisinin and combination therapies (ACT), and the parasite has become less sensitive to the Artemisinin component,” explained Dondorp. “In addition to that, we see more and more resistance to the partner drugs in these combination therapies. So we have six different ACTs, and for instance in Cambodia only two out of those six can be used.”
With the whole world now absorbed by Covid-19, and rightly so, there is always a danger that other important diseases like malaria are neglected
But despite the apparent resistance, most countries are on track to eliminate falciparum malaria within the next three years, but “it will need everyone’s hard work and dedication”, Dondorp stated.
Falciparum is the deadliest parasite in humans and resulted in 405,000 deaths globally in 2018, but the correct dose of Artemisinin and combination therapies kills all the malarial parasites living within the body. The less deadly but more complex plasmodium vivax strain, which accounts for about 72% of malaria cases in Southeast Asia, is more difficult to kill. The parasite hibernates within the person’s liver only to be released into the bloodstream weeks after initial treatment.
“We can still treat the infection, but it’s getting more and more difficult because we are slowly losing all the drugs [to resistance]. We have to push really hard now. If you take your foot off the accelerator, a resurgence will be very likely and that resurgence will be with very resistant malaria strains,” he warned.
RAI has recently been allocated another $240 million for the next three year period to 2023, on top of the $355 million they have already been granted by the Global Fund since they began in 2013. Dondorp says this gives countries a major incentive to keep motivated. “People are predicting this big money available at the moment won’t last forever, so we have to make a big push now for all this.”
After eradication, Dondorp says the next critical step will be to ensure surveillance is continued by village malarial workers to provide rapid malarial diagnostic tests for patients. “Once it’s gone, you still need some form of surveillance, to make sure if fever patients are detected that have malaria, they are still being captured.”
The real threat now, Dondorp says, is time.
“The danger is that already the number of malaria patients is becoming very, very low, so people lose their interest in malaria and start to forget what a terrible disease it is,” he explained. “With the whole world now absorbed by Covid-19, and rightly so, there is always a danger that other important diseases like malaria are neglected.”
